Protein based affinity chromatography has been widely used in purification of protein, DNA, and other chemical and biological molecules in various scales, ranging from laboratory, pilot to production scales. See, e.g., Hermanson et al., Immobilized Affinity Ligand Techniques, Academic Press, Inc. San Diego, Calif., pgs. 317-346 (1992). Among them, protein A (PrA), protein G (PrG) and protein L (PrL) based affinity chromatography resins are well known and widely used methods for detection and/or purification of immunoglobulins (Ig), however, they each have different specificities with respect to binding Ig.
As an example, PrA based reagents have especially found a widespread use in the field of biotechnology, e.g., in affinity chromatography for capture and purification of antibodies as well as in antibody detection methods. At present, PrA-based affinity media or resins probably are the most widely used affinity media for isolation of monoclonal antibodies and their fragments from different samples including cell culture. Accordingly, various matrices comprising protein A-ligands are commercially available including, for example, ProSep®-vA High Capacity, ProSep® vA Ultra and ProSep® UltraPlus (Millipore) and Protein A Sepharose™, rmp Protein A Sepharose Fast Flow, MabSelect™, MabSelect Xtra™ and MabSelect SuRe® (GE Healthcare), Poros MabCapture A (Applied Biosystems) and Sartobind Protein A (Sartorius).